Knee control mechanism for electric-sewing-machine cabinets



July 16, 1929. 'D. H. @9 50; 1,721,070

KNEE CONTROL MECHANISM FOR ELECTRIC SEWING MACHINE CABINETS Filed June 9, 1928 2 Sheets-Sheet 1 INVENTOR J ATTORNEY July 16, 1929. c so I 1,721,070

KNEE CONTROL MECHANISM FOR ELECTRIC SEWING MACHINE CABINETS Filed. June 9; 1928 2 Sheets-Sheet 2 INVENTOR fiarzz'e/ Efasom w|TN Es BY g'W 1W 7 ATTORNEY Patented July 16, 1928 UNITED sra'rr.

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DANIEL I-I. CHASON, OF ELIZABETH, NEW JERSEY, ASSIGNOR- TO THE SINGER MANU- FACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

KNEE CONTROL MECHANISM FOR ELECTRIO-SEXVING-MACHINE CABINETS.

Application filed June 9,

This invention relates to electric sewing machines of the cabinet type and has for an object to provide a simple and inexpensive form of knee-control mechanism adapting a sewing machine n'lo'tor-controller of the standard straight-pull or draw-bar Operated type for installation in a sewing machine cabinet or table.

To this end the controller-unit is mounted adjacent the end wall of the cabinet or table in an inclined position; the free end of the draw-bar of the controller-unit being inclined upwardly and toward the front of the table from the controller-body. At its free end the controller oieratin drawbar is connected to one arm of a bellcrank-lever operating in a plane normal to the-plane of the base-platc of the controller-unit. The other arm of the bellcrank-lever extends in the same general direction as the draw-bar and is connected to the upper end of a kneeshift lever which is mounted in an oppositely inclined position, whereby the lower end of the kneeshift lever is carried forwardly and disposed below the lower edge of the front wall or panel of the sewing machine cabinet, in a position for convenient knee-operation. The controller-unit, bcllcrank-lever and knee-shift lever are preferably mounted on a supporting plate which is secured to the. end-wall of the sewing machine table. The kneeshift lever preferably includes a curved extensible portion which is adjustable to suit the operator.

In the accompanying drawings, Fig. 1 is a front elevation of an electric sewing ma chine cabinet outfit embodying the invention. Fig. 2 is an inner face view of the end-wall of the cabinet showing the motor-controller operating mechanism. Fig. 3 is an elevation looking in the direction of the arrows 3, 3, Fig. 2. Fig. 4 is an elevation looking in the direction of the arrows 4, 4, Fig. 2, and Fig. 5 is a disassembled perspective view of the extensible arm of the knee-shift lever.

The invention is shown as embodied in a drop-head sewing machine cabinet or table having a top 1, end walls 2, 3, front wall or panel 4 and rear wall 5 defining the usual cavity into which the sewing machine head 6 and its driving motor 7 are lowered when not in use.

Secured to the inner side of the end wall 3 is a supporting base 8 to which is secured 192-8. Serial No. 284,181.

by screws 9 a standard straight-pull or drawbar operated sewing machine motor-controller of the carbon-compression type, such as disclosed in my copending applications Serial No. 240,587,1iledDec. 16, 1927, and Serial Nos. 284,180 and 284,182, filed herewith. Such a controller-unit comprises a base-plate 10 to which is fastened by screws 11 a carbon compression type rheostat 12 including a pull-rod 13 on which is screwed a head 14 embraced by the ends of the arms 15 which extend inwardly from the side members 16 at the ends of the cross-head 17 connected to the draw-bar or straight-pull operating member 18 which passes through an apera ture 19 in the wall 20 bent upwardly from the base-plate 10. Recovery springs 21 serve to restore the draw-bar to initial or off positionwhen the pull thereon is relieved.

The controller-unit is mounted in an inclined position, Fig. 2, adjacent the end wall 3 of the table, so that the free end of the. drawbar 18 extends upwardly and forwardly or toward the operator from the controller-body '12. Spot-welded to the plate 8 is the foot 22 of a bracket 23 on which is fulcrumed at 24 a bellcrank-lever the arm 25 of which is slotted at 26 to operatively engage the stud-screw 27 secured to the draw-bar 18. The other arm 28 of the locllcrank-lever projects through the aperture 29 in the knee-shift lever 30 to be described. The bellcrank-lever 25, 28 is disposed to operate in a plane transverse to the plane of the plate 8 and end-wall 3.

The knee-shift lever 30, Fig. 2, is inclined oppositely to the controller-unit and is fulcrumed at 31 on the bracket 32 which is spotwelded to the plate 8. The plane of operation of the knee-shift lever 30 is transverse to the plane of operation of the bellcrank-lever 25, 28 and is also transverse to the plane of the base-plate 8.

The knee-shift lever 30 includes a section 33 which is swingable about the pivot-screw 34 to the concealed or non-operating position, shown in dotted lines in F 2. 'The section 33 of the knee-shift lever includes the curved extensible knee-engaged portion 35 which is formed with a slot 36 to receive the guidetongue 37 bent upwardly from the end of the member 33. The member 33 is formed at its lower curved end with a slot 38 through which passes the shank of the thumb-screw 39 threaded into the member 35. The curved extensible portion 35 of the knee-lever is adjustable, as shown in Fig. 1, to suit the operator.

By referring to Fig. 2 it will be seen that when the swingable section 33 of the kneeshift lever is in its operative or full-line position, the lever as a whole lies substantially in a plane, so that the point of application of the knee-pressure is in the plane of operation of the straight portion 30 of the lever. This avoids any cramping action upon the fulcrum support 32 and also avoids any tendency for the knee-pressure to swing the sect-ion 33 about the screw 3%.

The rheostat 12 is connected in series with the motor 7 to the usual current supply outlet by suitable wiring.

It will be understood that by arranging the controller-unit and knee-shift lever at opposite inclinations adjacent the end wall or the sewing machine table, a standard straightpull controller unit, common to various types of electric sewing machine outfits, is adapted for knee-shift operation in a cabinet outfit; the operating mechanism being of the simplest character with a bellcrank-lever as the only intermediate element in the train of connections between the knee-shift lever and the draw-bar of the standard controller unit.

Having thus set forth the nature of the invention, what I claim herein is:

1. The combination with a. sewing machine table having an end wall, of a draw-bar operated sewing machine motor-controller unit mounted adjacent the inner side of said endwall in an inclined position with the free end of the draw-bar extending upwardly and forwardly or toward the operator from the controller-body, a bellcrank-lever disposed to operate in a plane transverse to the plane of the end-wall of the table and having one of its arms connected to the draw-bar of the controller, and a knee-shift lever inclined oppositely to the controller-unit and connected at its upper end to the other arm of said bellcrank-lever.

2. The combination with a supporting plate, of a draw-bar operated sewing machine motor-controller unit mounted on said plate so that the direction of pull of the draw-bar is substantially parallel to the latter, a bellcrank-lever fulcrumed on said plate to operate in a plane transverse to the latter, one arm of said bellcrank-lever being connected to said draw-bar, and a knee-sh1tt lever tulcrumed on said plate and connected to the other arm of said bellcrank-lever, the plane of operation of the knee-shift lever being transverse tosaid plate and to the plane of operation of said bellcrank-lever.

3. The combination with a sewing machine table having an end-wall, of a sewing machine motor-controller unit mounted adjacent said DANIEL H. OI-IASON. 

